Twelve members of a local gang were arrested for protesting against a raid to nab its leader in West Bengal's Hooghly district on Saturday, police said.
Acting on a tip-off, police raided Rabindranagar area of Chinsurah early on Saturday to arrest history-sheeter Totan Mallick, when his supporters opened fire and lobbed bombs, enabling his escape, Chandernagore Police Commissioner Humayun Kabir said.
"Mallick's men had set up CCTV cameras in the area and were alarmed by the footage of police approaching," Kabir said.
The gangster's supporters also blocked the Grand Trunk Road by burning tyres on Saturday morning following which 12 of them were arrested, he said.
Police said Mallick's name features in a number of murder cases, and is also accused of extorting money from builders and businessmen of the area.